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The Greeks invented the watermill sometime around the 3rd century BC and until very recently the basic design of a wheel and cogs has been used throughout the world to harness modest water flows and power machinery.

Modern technology has moved on a little bit since ancient Greece, but we’re slowly coming back around, like the wheel of a churning watermill, to the idea that there’s some value in the small.

Micro and pico hydropower systems can be as small as a medium-sized duck, and equally benign from an ecological point of view. They can also be a bit bigger, like the system Yellowstone National Park just put in place in order to power about a third of its operations through clean energy.

The stream in Yellowstone flows at a steady clip, but is not exactly visually overwhelming. There are bigger hydro sources out there: you don’t need to go over Niagara Falls in a barrel to have a sense of how much raw power is contained in that 50m cascade. That’s why the falls have been home to power plants on both sides of the border for over two hundred years. But streams and flows like that found in Yellowstone are both a good deal more common and surprisingly productive from an energy-producing point of view. Yellowstone authorities estimate their micro hydroplant’s potential to be in the neighbourhood of 1GW annually, which is still almost a quarter of Niagara Falls’ 4.4GW total capacity.

Others have gone much smaller. The Government of Sri Lanka recently signed off on a project to develop 19 separate micro hydro projects scattered throughout the country, generating a combined total of 1.3MW.

Even smaller are pico hydropower projects, generating no more than a few watts of power. They’re the kind of really small-scale technology that has slipped out of the cultural eye in the last century or so, as our electricity generating and distribution system becomes bigger and more sophisticated.

Green energy and a renewed interest in off-grid electricity supplies have put tiny, decentralized technologies like pico power back on the map. Canada only has one Niagara Falls, but we have plenty of flowing water and a nearly infinite number of waterways capable of producing at least a couple watts.

Windmills have more or less gone the way of the dodo in Africa as well, but it’s a continent that has not forgotten about the value of small-scale solutions, and perhaps unsurprisingly, it’s here that we find the world’s highest concentration of pico hydropower systems already in use.

For a handful of remote communities near Mount Kenya, pico power provides the ability to recharge radios and cell phones and gives light to read or study by after dark. There is no massive coal plant to replace, but even here an environmentally friendly option eases reliance on the more dangerous kerosene lamps. Without making too many generalizations about Africa, there are many places in the vast continent where villages have access to flowing water, but not to electricity. Pico hydro can be the lowest cost option for these communities.

Energy independence is a term that I write with a great deal of hesitation, because it has been used so often to justify exploiting the most environmentally irresponsible resources one can dig up from one’s own soil. But if I may engage in a small reclamation project, I think the phrase may have some utility left in it as the descriptor for an ethic which uses the renewable resources we have – however small – to achieve independence from fossil fuels. Yellowstone and the communities of Mount Kenya have both found their version of energy independence through micro or pico hydropower. There’s no question that Canada’s endless waterways contain the same potential.

Stu Campana is an international environmental consultant, currently working with Fern Ridge Landscaping and Eco-Consulting in Milton, Ontario.

Stu Campana is an international environmental consultant, with expertise in water, energy and waste management. He is the Water Team Leader with Ecology Ottawa, has a master’s in Environment and Resource Management and writes the A\J Renewable Energy blog. Follow him on Twitter: @StuCampana.

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